Property owners in the central waterfront zone in Portland are generally-and perhaps surprisingly-optimistic about plans to convert the giant Cumberland Cold Storage building on Merrill Wharf into office space for northern New England’s largest law firm.

“The ripple effect will be huge,” predicts Charlie Poole, owner of neighboring Union Wharf and a well-regarded spokesman for waterfront property owners. “I think [the project] will be good for the waterfront. It will be very good to see that building being used and rehabilitated.”

Rumors began circulating in early spring that Pierce Atwood was looking for new office space. The law firm and its 175 employees have been headquartered at One Monument Square since the late 1970s, occupying six floors and 75,000 square feet of space in downtown Portland.

In early May, Waterfront Maine, owner of the Cumberland Cold Storage building, approached the Portland City Council to request a $2.6-million tax break to help finance a $12-million renovation of the five-story, 100,000-square-foot structure into office space for Pierce Atwood. Without the tax break, councilors were warned, the law firm would likely move to new digs in South Portland or elsewhere.

Despite grumblings from some quarters over the heavy-handed threat, by early June the tax break and necessary zoning changes flew through the city council and the planning board. Under the terms of the agreements, Waterfront Maine’s tax bill for the next 20 years is capped at $2.9 million, just over half the amount it would have paid otherwise after renovations. Currently the building, which has almost no plumbing and windows filled with concrete, is valued at $950,000 and pays less than $17,000 a year in property taxes, according to city officials.

“It’s important to note that this entire project is consistent with the existing waterfront zoning,” says Greg Mitchell, Portland’s economic development director. The building’s first floor will be retained for marine uses, as will the six existing berthing spots, while the renovations will include a five-to-seven-foot walkway along the pier’s bulkhead with space for lobstermen to stack their traps. Pierce Atwood will occupy the upper four floors.

“It’s a wonderful example of how mixed-use development can occur along the waterfront,” Mitchell says. “It will improve connectivity between the street and the waterfront and enhance space for marine activities.”

The brick structure was built approximately 150 years ago to store rum and molasses. It survived the Great Fire of 1866, and over the years has seen a number of uses. In the 1980s a developer announced plans to turn it into a condominium complex, sparking a battle that helped create the waterfront preservation movement. At one time the building was also eyed as part of a planned aquarium and marine research facility. Waterfront Maine bought the building, as well as Fort Andross in Brunswick, in a foreclosure auction in 1986.

Poole emphasizes that the project has no connection to efforts by himself and other waterfront property owners to change the zoning in the central district to allow a 50-50 mix of marine and non-marine uses in first-floor spaces and pier surfaces.

“The fishing industry has pretty much gone south, in more ways than one,” notes Richard “Dick” Ingalls, who has been working with Poole on the zoning change. “There’s more than enough space now for the lobstermen who remain.”

Poole says the ability to lease space to non-marine businesses in the upper floors of the buildings on his wharf has allowed him to rebuild most of Union Wharf. “We would never have been able to do all the work we’ve done without that added income,” he explains. “We’ve put up seven or eight new buildings and rebuilt virtually the entire perimeter, as well as dredged it out.”

The Pierce Atwood project will have long-term effects on the waterfront, Poole says. “We’re seeing major investments in a building that has seen minimal use up to now,” he offers. “This will bring more people down here, more ancillary businesses, more visitors, more meetings. People are going to put more money into our waterfront economy. I think that’s all pretty positive.”